L’immaginario geometrico dell’uomo che delibera. Schemi di esercizio della "phantasia bouleutiké" in Aristotele,

The paper begins with the discussion of De anima, III, 11, 434a7-10:unlike the best known interpretations of the passage, which considerably depend on Philoponus’ commentary, here we try to reconstruct the measurement activity, presented in a relationship of analogy with the “deliberative imagination”, in the light of procedures of decomposition and recomposition of geometrical figures, which were widely spread in the V-IV centuries B.C., of which numismatic illustrations are also offered. It is possible to understand in the same line the reference both to the “analysis” of figures in Nichomachean Ethics, III, 5, 1112b20-21, and to the triangle as an “extreme” in Nichomachean Ethics, VI, 9, 1142a23. To this spatial-metretic model of the phantasia bouleutikē, a logistic-temporal one is added, mentioned in De anima, III, 7, 431b7-8 and De memoria, 2, 453a15-16, with an interesting confirmation in Thucydides, I, 138, 3, where Themistocles is compared to a “skillfull gnōmōn”. In both cases, the mathematical models that serve as inspiration to the man that imagines while trying to understand what is to act well, here and now, are not refined products of theoretical sciences, but part of those “merchants’ mathematics” which Plato advised not to practice in order to gain the vision of the true good.